Medical devices with detachable pivotable jaws

ABSTRACT

Medical systems, devices and methods are provided for engaging tissue, e.g. for clipping tissue, closing a perforation or performing hemostasis. Generally, the medical system including a housing, first and second jaws rotatable relative to the housing, a driver, and an elongate drive wire. The elongate drive wire may be disconnected from the driver, first and second jaws, and the housing, which are left in vivo engaged with the tissue.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 12/971,873 filed on Dec. 17, 2010, which claims the benefit ofU.S. Provisional Application Ser. No. 61/289,297 filed on Dec. 22, 2009,entitled “MEDICAL DEVICES WITH DETACHABLE PIVOTABLE JAWS,” and furtherclaims the benefit of the filing date under 35 U.S.C. §119(e) ofProvisional U.S. Patent Application Ser. No. 61/391,881 filed Oct. 11,2010. All of the foregoing applications are hereby incorporated byreference.

BACKGROUND

Conventionally, a clip may be introduced into a body cavity through anendoscope to grasp living tissue of a body cavity for hemostasis,marking, and/or ligating. Such clips are often known as surgical clips,endoscopic clips, hemostasis clips and vascular clips. In addition,clips are now being used in a number of applications related togastrointestinal bleeding such as peptic ulcers, Mallory-Weiss tears,Dieulafoy's lesions, angiomas, post-papillotomy bleeding, and smallvarices with active bleeding. Clips have also been attempted for use inclosing perforations in the stomach

Gastrointestinal bleeding is a somewhat common and serious conditionthat is often fatal if left untreated. This problem has prompted thedevelopment of a number of endoscopic therapeutic approaches to achievehemostasis such as the injection of sclerosing agents and contactthermo-coagulation techniques. Although such approaches are ofteneffective, bleeding continues for many patients and corrective surgerytherefore becomes necessary. Because surgery is an invasive techniquethat is associated with a high morbidity rate and many other undesirableside effects, there exists a need for highly effective, less invasiveprocedures.

Mechanical hemostatic devices such as clips have been used in variousparts of the body, including gastrointestinal applications. One of theproblems associated with conventional hemostatic devices and clips,however, is that many devices are not strong enough to cause permanenthemostasis. Further, clips have also been attempted for use in closingperforations in the stomach or gastrointestinal structures, butunfortunately traditional clips suffer from difficult placement and thecapability to grasp a limited amount of tissue, potentially resulting inincomplete closure.

BRIEF SUMMARY

The invention may include any of the following aspects in variouscombinations and may also include any other aspect described below inthe written description or in the attached drawings.

In a first aspect, a medical device is provided for engaging tissue, themedical device including a housing, first and second jaws, an elongateddrive wire, and a driver. The housing defines an internal passageway anda longitudinal axis extending between proximal and distal ends of thehousing. The housing also defines a driver guide surface along theinternal passageway. The first and second jaws are rotatable relative tothe housing, and each have proximal and distal ends. The driver has aproximal portion engaged with the drive wire and a distal portionengaged with the proximal ends of the first and second jaws.Longitudinal movement of the driver rotates the first and second jawsrelative to the housing. The driver also includes an intermediateportion positioned between the proximal and distal portions. Theintermediate portion includes a frame and a locking leg connected to theframe, the frame defining an intermediate space. The frame is deformablesuch that a predetermined longitudinal force differential between theproximal portion and distal portion of the driver causes the frame todeform and the locking leg to move away from the longitudinal axis intoa locking position for engaging the driver guide surface.

According to more detailed aspects, the length of the driver increasesupon deformation of the frame. The frame circumscribes the intermediatespace, and the intermediate space has a general C-shape prior todeformation of the frame, and a generally rectangular shape afterdeformation of the frame. The longitudinal distance of the intermediatespace increases after deformation, and the locking leg preferablyrotates away from the longitudinal axis. The driver may also include aneck interconnecting the proximal portion of the driver and theintermediate portion of the driver. In one variation, the neck isbreakable upon a second predetermined longitudinal force differentialbetween the proximal portion and the intermediate portion of the driver.The second predetermined longitudinal force differential is greater thanthe predetermined longitudinal force differential that deforms theframe. In another variation, the neck is not breakable, but rather theproximal portion and its socket deforms to allow the drive wire andrelated structures to be released, leaving the clip in vivo and lockedto the tissue.

According to still further detailed aspects, the frame preferablyincludes a proximal member extending laterally, a distal memberextending laterally, and a pair of side members connecting the proximaland distal members. The locking leg is connected to the distal memberand one of the side members, and the distal member defines a deformablearea adjacent the locking leg. In some constructions, the distal member,locking leg, and the one side member together deform under thepredetermined longitudinal force differential to move the locking legaway from the longitudinal axis. The locking leg may have a generalV-shape and define a portion of the intermediate space. The housing'sdriver guide surface includes a proximal portion and distal portion anda shoulder at the transition between of the proximal and distalportions. The shoulder faces proximally, and the locking leg ispositioned to engage the shoulder to limit longitudinal movement of thedriver after the locking leg has been moved laterally outwardly bydeformation of the frame of the driver.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification illustrate several aspects of the present invention, andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a top view of a medical system having a medical device forengaging tissue, constructed in accordance with the teachings of thepresent invention;

FIG. 2 is a top view similar to FIG. 1, but showing the outer structuresin dotted lines and the interior sections in solid lines and partialcross section;

FIG. 3 is a side view of the medical system and device depicted in FIG.1;

FIG. 4 is a side view similar to FIG. 3, but showing the outerstructures in dotted lines and the interior structures in solid linesand partial cross section

FIG. 5 is a side view of a medical device that is part of the medicalsystem depicted in FIGS. 1-4;

FIG. 6 is a front view of a housing forming a portion of the medicalsystem and device depicted in FIGS. 1-5;

FIG. 7 is a perspective view of the housing depicted in FIG. 6;

FIGS. 8-12 are side views showing operation of the medical system anddevice depicted in FIGS. 1-5;

FIGS. 13 and 14 are top views, partially in cross-section, depictingoperation of the medical system and device depicted in FIGS. 1-4;

FIGS. 15 and 16 are cross-sectional views showing operation of themedical system and device depicted in FIGS. 1-4.

FIGS. 17 and 18 are a perspective view of an alternate embodiment of agrasping jaw forming a portion of the medical system and device of FIG.1;

FIG. 19 is a plan view of an alternate embodiment of a driver forming aportion of the medical system and device of FIG. 1;

FIG. 20 is a perspective view of the driver of FIG. 19 shown attached toa drive wire;

FIG. 21 is a side view of FIG. 20;

FIG. 22 a is a plan view of an alternate embodiment of the medicaldevice of FIG. 1, and FIG. 22 b is a plan view of the driver of FIG. 19shown attached to a strip and forming a portion of the medical device ofFIG. 22 a;

FIG. 23 is a plane view of another alternate embodiment of the medicaldevice depicted in FIG. 1;

FIGS. 24 and 25 are a perspective views showing operation of the medicaldevice depicted in FIG. 23;

FIGS. 26 and 27 are perspective and end views, respectively, of anotherembodiment of a driver forming a portion of the medical system anddevice depicted in FIG. 1;

FIG. 28 is a perspective view of the driver of FIGS. 25-26 shownattached to the jaws;

FIGS. 29 and 30 are plan views showing operation of the driver and jawsdepicted in FIG. 28;

FIGS. 31 and 32 are cross-sectional views of another embodiment of themedical system and device depicted in FIG. 1;

FIG. 33 is a perspective view of the medical system and device depictedin FIGS. 31 and 32;

FIGS. 34-37 are plan views showing operation of another alternateembodiment of a driver forming a portion of the medical system anddevice of FIG. 1; and

FIG. 38 is a plan view of yet another alternate embodiment of a driverforming a portion of the medical system and device of FIG. 1.

DETAILED DESCRIPTION

The terms “proximal” and “distal” as used herein are intended to have areference point relative to the user. Specifically, throughout thespecification, the terms “distal” and “distally” shall denote aposition, direction, or orientation that is generally away from theuser, and the terms “proximal” and “proximally” shall denote a position,direction, or orientation that is generally towards the user.

An exemplary medical system 20 having a medical device 40 for engagingtissue T (FIG. 11) is shown in FIGS. 1 through 4. The medical system 20and device 40 are generally sized and structured for operation throughthe working channel of an endoscope (not shown) or other scope, althoughthe system 20 and device 40 may also be used alone or in conjunctionwith other elongate devices such as catheters, fiber-optic visualizationsystems, needles and the like. Generally, the medical system 20 includesa drive wire 22 slidably housed within the distal end 23 of an elongatedcatheter 24 for selective connection to, and operation of, the medicaldevice 40. As will be described in further detail herein, the medicaldevice 40 generally includes a housing 42 having a first jaw 44 and asecond jaw 46 pivotally connected thereto for engaging the tissue T.Generally, the jaws 44, 46 have been shown as forming grasping forceps,although the jaws are intended to be used to clip tissue, e.g. to closean opening or for hemostasis. Accordingly, it will be recognized thatthe shape and structure of the jaws may take many forms and serve manypurposes and functions, all in accordance with the teachings of thepresent invention.

In the medical system 20, the drive wire 22 slidably extends through thecatheter 24. Although the term “wire” is used to refer to the drive wire22, it will be recognized that any elongate control member capable oftransmitting longitudinal force over a distance (such as is required intypical endoscopic, laparoscopic and similar procedures) may be used,and this includes plastic rods or tubes, single filament ormulti-filament wires, metal rods and the like. The drive wire 22 shouldalso be capable of properly transmitting a rotational/torsional forcefrom the proximal end to the distal end to rotate the medical device 40and jaws 44, 46, and thus it is currently preferred that the drive wire22 is formed from nitinol (e.g. a nitinol wire) or other superelasticalloy. A connection block 26 is slidably fitted within the distal end 23of the catheter 24 and defines a bore 28 therethrough which slidablyreceives the drive wire 22. The exterior of the connection block 26includes a recessed portion 27, and two pins 30 (e.g., formed fromstainless steel wire) are connected to the catheter 24 and positionedwithin the recessed portion 27 to limit the longitudinal movement of theconnection block 26.

A distal end of the drive wire 22 defines a distal head 32 that is sizedlarger than the drive wire 22, and likewise larger than the bore 28 inthe connection block 26. As will be described later herein, the distalhead 32 is used to slide the connection block 26 within the catheter 24to disconnect the medical device 40 from the medical system 20. As alsoseen in FIGS. 1-4, the housing 42 of the medical device 40 is a tubularmember defining an interior space 43. A proximal end of the housing 42frictionally receives a distal end of the connection block 26 within theinterior space 43 for selective connection therewith.

The internal passageway 43 of the housing 42 also receives the first andsecond jaws 44, 46 and a driver 48 which is used to interconnect thedrive wire 22 to the jaws 44, 46. As best seen in FIGS. 1, 2 and 5, thedriver 48 has a proximal portion which defines a socket 50 sized toreceive enlarged distal head 32 of the drive wire 22. At the proximalentrance of the socket 50, two deflectable locking tabs 52 are formedwhich rotate relative to the remainder of the driver 48 to increase ordecrease the size of the socket 50. The locking tabs 52 may beseparately formed and pivotally attached to the driver 48, or may beintegrally formed with the driver 48 and formed of a resilient materialwhich flexes to permit rotation of the locking tabs 52 radially inwardlyand radially outwardly. A distal portion of the driver 48 defines a rack54 for engaging and operating the jaws 44, 46. In the depictedembodiment, the rack 54 includes a central spine 56 having teeth 58projecting away from the central spine 56 and on opposite sides of thespine 56. One set of teeth 58 on one side of the spine 56 generallyoperate the first jaw 44 while the other set of teeth 58 on the otherside of the spine 56 operate the second jaw 46. It will be recognizedthat the rack 54 may include a single set of teeth or other gearedstructures that interface with the jaws 44, 46.

As best seen in FIG. 5, the first and second jaws 44, 46 include distalends 60, 62 that are structured to grasp and engage tissue, generallythey have a talon shape as disclosed in 61/141,934 filed Dec. 31, 2008,the disclosure of which is incorporated herein by reference in itsentirety. The proximal ends 64, 66 of the first and second jaws 44, 46each include a pinion gear 68, 70 having a series of teeth. The teeth ofthe pinion 68, 70 mesh with the teeth of the rack 54 of the driver 48such that longitudinal translation of the driver 48 induces rotation inthe first and second jaws 44, 46 relative to one another. Generally,distal translation of the driver 48 causes the first and second jaws 44,46 to rotate outwardly away from each other, while proximal retractionof the driver 48 causes the first and second jaws 44, 46 to rotateinwardly toward one another. Pins 80 are fitted through each theproximal ends of the jaws 44, 46, to pivotally connect the jaws to thehousing 42. Other structures for forming a pivotal connection may beused, and preferably the pivotal connection is centrally arrangedrelative to the pinions 68, 70.

In addition to the jaws 44, 46 being pivotally attached to the housing42, the first and second jaws 44, 46 are also slidably attached to thehousing 42. As best seen in FIGS. 6 and 7 (and in conjunction with FIGS.1-4) the housing 42 defines a first guide surface 82 for the first jaw44, and a second guide surface 84 for the second jaw 46. As seen in FIG.3, the first and second guide surfaces 82, 84 are formed by elongatedslots 82 a, 82 b, 84 a, 84 b formed in opposing sides of the housing 42which leaves a thickness of the housing 42 exposed to serve as the guidesurface. The slots 82 a, 82 b are aligned to receive the connecting pin80 of the first jaw 44, and likewise the slots 84 a, 84 b are aligned toreceive the connecting pin 80 of the second jaw 46. The ends of theslots, for example distal ends 92, 94 shown in FIG. 7, serve to restrictthe longitudinal movement of the jaws 44, 46 relative to the housing 42.The proximal ends 64, 66 of the jaws 44, 46 include apertures 72, 74which receive the pins 80 (FIGS. 1, 2 and 3) that are used to slidablyand pivotally connect the first and second jaws 44, 46 to the housing42.

It can also be seen in FIGS. 6 and 7 that the housing 42 defines a thirdguide surface 86 which guides the longitudinal movement of the driver 48within the housing 42. The guide surface 86 in the depicted embodimentincludes a left guide surface 86 a and a right guide surface 86 b formedas C-shaped channels. As shown in FIG. 7, the third guide surface 86transitions from a smaller proximal width to a larger distal width todefine a shoulder 88 at the transition, which will be further describedhereinbelow with reference to FIGS. 13 and 14.

As also shown in FIG. 6, the internal passageway 43 of the housing 42extends through the distal end of the housing, and through which thefirst and second jaws 44, 46 can extend. Additionally, as shown in FIGS.1 and 2, the housing 42 defines opposing slots 45 which are sized topermit the first and second jaws 44, 46 to pass therethrough when theyrotate radially outwardly. Accordingly, it is also clear from FIGS. 1and 2 that the housing 42 serves to block rotation of the first andsecond jaws 44, 46 when they are entirely or partially contained withinthe internal passageway 43 of the housing 42. Suitable plastics forforming the housing include, but are not limited to,polytetrafluorethylene (PTFE), expanded polytetrafluorethylene (EPTFE),polyethylene ether keytone (PEEK), polyvinylchloride (PVC),polycarbonate (PC), polyamide, polyimide, polyurethane, polyethylene(high, medium or low density), and suitable metals include stainlesssteel, nitinol and similar medical grade metals and alloys.

Operation of the medical device 40 will now be described with referenceto FIGS. 8-12. As shown in FIG. 8, the first and second jaws 44, 46 areshown in a retracted position where they are substantially containedwithin the housing 42. Depending on the application, the distal ends 60,62 of the jaws 44, 46 may slightly project from the distal end of thehousing 42 in their retracted positions, or they may be entirelypositioned within the housing 42. When the drive wire 22 is translateddistally (to the right on the page in FIG. 8) the distal head 32 engagesthe driver 48, the driver 48 and jaws 44, 46 slide distally through thehousing 42. The driver 48 and jaws 44, 46 slide longitudinally beforethey rotate (even though the rack 54 of the driver 48 is meshed with thepinions 68, 70 at the proximal ends 64, 60 of the jaws 44, 46) since theresistance to longitudinal movement is less than the force required torotate the jaws 44, 46 (alternatively, the housing 42 can block rotationof the jaws 44, 46 when they are within the housing 42). As previouslymentioned, this longitudinal movement is guided by the first and secondguide surfaces 82, 84 which receive the pins 80 that slidably andpivotally connect the jaws 44, 46 to the housing 42.

As shown in FIG. 9, the first and second jaws 44, 46 have an extendedposition where the jaws substantially project from a distal end of thehousing 42, and their proximal ends 64, 66 are positioned adjacent thedistal end of the housing 42. Accordingly, it will be seen that furtherdistal advancement of drive wire 22, and hence the driver 48, causes thepinion 68 to rotate over the teeth 58 of the rack 54. As best seen inFIG. 10, the first and second jaws 44, 46 rotate radially outwardly fromeach other into a tissue receiving position. Notably, due to thepresence of slots 45 at the distal end of the housing 42, the jaws 44,46 are permitted to rotate a full 90°, thus forming at least a 180°between them. It will be recognized that through the sizing of the slots45 and the construction of the rack 54 and pinions 68, 70, the first andsecond jaws 44, 46 may rotate even further away from each other.

In the tissue receiving configuration shown in FIG. 10, the medicaldevice 40 and its jaws 44, 46 may be positioned adjacent tissue T. Asshown in FIG. 11, the tissue T may be placed between the first andsecond jaws 44, 46 and the jaws 44, 46 rotated back towards theirposition shown in FIG. 9. The tissue T has been shown as a single layer,although multiple layers may be clipped between the jaws 44, 46.Generally, proximal retraction of the drive wire 22 and the driver 48again causes rotation of the first and second jaws 44, 46 to grasp thetissue T therebetween. As shown in FIG. 12, further proximal retractionof the drive wire 22 and driver 48 will cause the jaws 44, 46 to movelongitudinally in a proximal direction (to the left on the page in FIG.12).

In order for the medical device 40 to serve as a clip and maintain itsgrasp on the tissue T, or to maintain the clipping of two layers oftissue against each other, the jaws 44, 46 may be locked in position andthe drive wire 22 of the medical system 20 disconnected from the medicaldevice 40. As shown in FIG. 13, the third guide surface 86 (which guidesthe driver 48) includes a proximal portion 86 p and a distal portion 86d. The proximal portion 86 p of the third guide surface 86 has a width(measured up and down on the page in FIG. 13) that is greater than awidth of the distal portion 86 d of the third guide 86. As previouslydiscussed, the third guide surface 86 is formed by opposing surfaces orC-shaped channels 86 a, 86 b of the housing 42. The transition betweenthe proximal portion 86 p and distal portion 86 d defines a shoulder 88,and namely two shoulders 88 a, 88 b on opposing sides of the housing 42.The shoulders 88 a, 88 b are sized and positioned to engage the lockingtabs 52 located on the driver 48.

As shown in FIG. 13, when the driver 48 is located within the distalportion 86 d of the third guide surface 86, the locking tabs 52 areforced radially inwardly into firm frictional engagement with the drivewire 22. Stated another way, the socket 50 formed by the driver 48 toreceive the distal head 32 has an entrance which is narrowed by theinward deflection of the locking tabs 52. Preferably, the locking tabs52 plastically deform rather than elastically deform, and the tabs 52may be bent inwardly around the distal head 32 during initial assemblyof the device, and thus sized for the distal portion 86 d of the thirdguide surface 86. In this state depicted in FIG. 13, the drive wire 22is firmly engaged with the driver 48 and hence the first and second jaws44, 46.

When the drive wire 22 and driver 48 are retracted proximally, forexample upon grasping tissue as shown in FIG. 12, the proximal end ofthe driver 48 is received within the proximal portion 86 p of the thirdguide surface 86 which has a larger width that permits radially outwardmovement of the locking tabs 52. Accordingly, in the state depicted inFIG. 14, the locking tabs 52 may be loosely and detachably connected tothe distal head 32 of the drive wire 22. That is, the proximalretraction of the jaws 44, 46 will be limited by either the tissue Tengaging the distal end of the housing 42, or the pins 80 will abut theproximal ends of the slots 82 a, 82 b, 84 a, 84 b defining a first andsecond guide surfaces 82, 84. As such, when proximal movement of thejaws 44, 46 and the driver 48 are thus limited, further proximalmovement of the drive wire 22 and its distal head 32 may be used towithdraw the distal head 32 from the socket 50 of the driver 48. Thisoperation may also be used to further deflect the locking tabs 52radially outwardly. An appropriate amount of distally directed force onthe drive wire 22 causes the distal head 32 to move proximally throughthe locking tabs 52 and plastically deform them radially outwardly. Inthe event the natural elasticity of the tissue T tends to pull the jaws44, 46 out from the housing towards their extended position, the lockingtabs 52, 54 will abut the shoulders 88 a, 88 b of the third guidesurface of the housing 42 to prevent further distal movement of the jaws44, 46.

Turning now to FIGS. 15 and 16, upon still further proximal retractionof the drive wire 22 and distal head 32, the enlarged distal head 32will abut the connection block 26 which is slidably fitted within thedistal end 23 of the catheter 24. Sufficient proximal force on the drivewire 22 will overcome the frictional fit between the connection block 26and the proximal end of the housing 42, thus moving the connection block26 proximally (to the right on the page of FIGS. 15 and 16) to retractthe connection block 26 within the tubular connector 24, as shown inFIG. 16. The catheter 24 can be used to provide a counterforce on thehousing 42 while proximally retracting the drive wire 22 and connectionblock 26. Accordingly, the drive wire 22, catheter 24 and connectionblock 26 may be fully disconnected from the medical device 40, therebyleaving the first and second jaws 44, 46 and the housing 42 in a statehaving the tissue T clipped between the jaws 44, 46 and retained invivo. The connection block 26 is retained at the distal end 24 of thecatheter 24 via the pins 30, which are positioned within the recessedarea 27 to engage the proximal and distal ends of the connection block26 and limit its longitudinal movement.

The elongated catheter 24 (or other elongate tubular member such as asheath, tube, scope or the like), which slidably encases the drive wire22, extends proximally therealong to a proximal end of the system 20,and has a length suitable for placing the device 40 at any desiredlocation within the body, while the proximal ends of drive wire 22 andcatheter 24 are positioned outside of the body for use by the medicalprofessional. Control handles (not shown) for controlling relativetranslation of the drive wire 22 and catheter 24 are well known in theart, and may be employed at the proximal end of the system 20.

Another embodiment and method of forming the grasping jaws 44, 46 areshown in FIGS. 17-18. The jaws of the prior embodiment were generallymachined, however the jaws 44, 46 may also be formed by stamping. A flatpiece of metal preferably of medical grade stainless steel, is stampedinto the shape 144 shown in FIG. 17. The shape includes a slightlynarrow distal end 160 which then can be bent into the shape shown inFIG. 18 for grasping and engaging tissue. The distal end 160 may also bestamped to include a serrated edge, or other shapes or edge featuresdepending upon the application. The proximal end 164 generally includestwo arms 166 which lead to gears 168. As shown in FIG. 18, the gears 168are grasped and then rotated about 90 degrees such that the gears 168extend in a plane that is perpendicular to the plane of the sheet 144.The gears 168 also include a through-hole 172 for receiving a guidingpin. It will also be recognized that the jaws 44, 46 in this embodimentmay also be formed of a single arm 166 and single gear 168.

Another embodiment of a driver 148 and drive wire 122 are shown in FIGS.19-22. The driver 148 generally includes a socket 150 formed by twolocking tabs 152. In this embodiment, a proximal portion of the lockingtabs define slanted shoulders 154 which slope laterally outwardly forengagement with the third guide surface 86 in the housing 42 aspreviously discussed. The locking tabs 152 also include innerprojections 153 which project laterally inwardly and separate the socket150 into a distal portion 150 d and a proximal portion 150 p. The driver148 again includes a central spine 156 and opposing teeth 158. In thisembodiment, the distal end 166 of the driver 148 includes a pocket 168defined by two inwardly projecting flanges 170, as will be discussedfurther herein. The two flanges 170 extend along a distal side of thepocket 168, and leave a gap therebetween for access to the pocket 168.

As seen in FIGS. 20 and 21, this embodiment of the drive wire 122includes a distal head 132 which is formed by bending the distal end ofthe drive wire 122 into a semi-circular shape as shown, preferablyspanning an arc of 180 degrees to 360 degrees. Accordingly, it can beseen that the distal head 132 defines an opening 133 that is sized toreceive the inner projections 153 of the locking tabs 152. As shown, thedistal portion 150 d of the socket 150 receives the distal-most part ofthe curved distal head 132, while the proximal portion of the distalhead 132 projects through the proximal portion 150 p of the socket 150and proximally away therefrom. As noted above, the locking tabs 152 hereare structured to be plastically deformed, and thus after formation andconnection to the drive wire 122 as shown in FIG. 19, the tabs 152 arebent radially inwardly to secure the projections 153 within the opening133 of the socket 132. In this state, the exterior shoulders 154 of thelocking tabs 152 are sized to fit within the third guide surface 86, andmore particularly the distal portion 86 d of the third guide surface 86without further deformation.

As shown in FIGS. 22 a and 22 b, another embodiment of the medicaldevice 140 may include the housing 142, grasping arms 144, 146 just asin the prior embodiment, but in this embodiment include the alternatedriver 148 and an additional biasing element, namely a biasing strip190. As best seen in FIG. 22 b, the distal end 166 of the driver 148receives the biasing strip 190 within the pocket 168. The flanges 170are bent inwardly and proximally as shown to firmly engage the metalstrip 190 and fix it to the driver 148. The biasing strip 190 ispreferably a thin strip formed from a sheet of resilient material, andmore preferably a metal strip, e.g. formed of stainless steel, nitinolor other super elastic alloy that is biocompatible. Accordingly, it willbe recognized that as the driver 148 is moved proximally to cause thejaws 144, 146 to close, the biasing strip 190 will be forced into aV-shape or U-shape, as shown by the dotted lines in FIG. 22 a. That is,the biasing strip 190 has a straight shape in its natural, unbiased,configuration, and when bent into the V-shape it exerts a radiallyoutward force on the jaws 144, 146. This biasing force provides the jaws144, 146 with smooth rotation and transition between the open and closedpositions. It will also be recognized that the biasing strip 190 couldalso have its original, unbiased position formed as a V-shape or aU-shape, and be affixed to the jaws 144, 146 such that it exerts aradially inward biasing force. The free ends 192 of the metal strip 190simply press against the jaws 44, 46, but are not fixed or rigidlyattached thereto.

Turning to FIG. 23, another embodiment of the medical device 240 isshown, again including a housing 242 and opposing jaws 244, 246 that areslidably attached thereto. The housing 242 again includes first andsecond guides 282, 284 for guiding movement of the jaws 244, 246. Inthis embodiment however, each jaw 244, 246 includes a biasing strip 290a, 290 b, respectively. The distal ends 291 of the strips 290 a, 290 bare fixedly attached to the exterior of the jaws 244, 246, preferably attheir distal ends, and preferably by way of an adhesive, soldering,welding, or other known bonding techniques. As best seen in FIGS. 24 and25, the housing 240 includes two exterior channels 294 on opposite sidesof the housing 240 (one being shown in FIGS. 24 and 25) which are sizedto receive the resilient strips 290 a, 290 b such that they are flushwith the exterior surface of the housing in the closed/retractedconfiguration. The proximal ends 293 of the strips 290 a, 290 b includea T-shaped formed by a base 295 and cross bar 296. The base 295 extendsthrough a smaller slot 296 formed through the housing 240. The slots 296are coextensive with the channels 294. The cross bar 296 rides along theinterior of the housing 240 and maintains the slidable connectionbetween the strips 290 and the housing 240. Accordingly, it can be seenthat the proximal ends 293 of the strips 290 a, 290 b are slidably andpivotably attached to the housing 240 via the channel 294 and its slot296, allowing the strips 290 a, 290 b to travel with the grasping jaws44, 46 as shown between their open and closed positions as shown inFIGS. 24 and 25.

Turning now to FIGS. 26-30, another embodiment of a driver 348 is shown.As best seen in FIGS. 26 and 27, the driver 348 again includes a socket350 formed by two locking tabs 352 which have inner projections 353 andouter shoulders 354, and which divide the socket 350 into a distalportion 353 and a proximal portion 350 p. Unlike the prior embodimentsof the driver, in this embodiment the distal portion defines a gearedrack that has a Z-shape. Generally, a central plate 356 replaces thecentral spine 56, 156 of the prior embodiments, and the plate 356extends in a plane that is parallel to the longitudinal plane of thehousing 342 (FIG. 29). The plane of the central plate 356 is alsoperpendicular to a plane of the proximal half of the driver 348 (i.e.that which includes the socket 350 and tabs 352). A first set of teeth358 a project laterally away from the central plate 356 in a firstdirection, while a second set of teeth 358 b project laterally away fromthe central plate 356 in a second direction. The first and second setsof teach 358 a, 358 b extend from opposite ends of the central plate356, and the first and second directions are generally opposite eachother. The sets of teeth 358 a, 358 b are each securely held to thecentral plate 356 by two outer frames 360 which extend around theperiphery of the teeth 358 a, 358 b.

Accordingly, and as best seen in FIG. 28, the medical device 340includes first and second grasping jaws 344, 346 each having a proximalend 366 and gear teeth 368 which have been bent to project orthogonallyaway from a main body of the jaw 344. Accordingly, the first set ofteeth 358 a receive the gear 368 of the second jaw 346, while the secondset of teeth 358 b receive the gear 368 of the first jaw 344. Notably,having the proximal ends 366 of the jaws 344, 346 bentlaterally/orthogonally as shown allows a single pin 380 to be passedthrough the gears 368 and thus shared by both jaws 344, 346. Stillfurther, and as shown in FIG. 29, the housing 342 may thus include onlya single guide surface 382 formed by a single slot on each lateral sideof the housing 342 for receiving the ends of the single pin 380. It canbe seen that the first and second jaws 344, 346 thereby share a singleguide surface 382 (a jaw guide surface) and guide slot, thus ensuringtheir coordinated operation and smooth opening and closing.

As also shown in FIG. 29, a slot 357 is formed in the central plate 356,and is aligned with the pin 380 and jaw guide surface 382 to receive thepin 380 as the driver 348 moves forwardly relative to the jaws 344, 346.As discussed above and shown in FIG. 30, when the pin 380 (shared byproximal ends 366 and gears 368 of the jaws 344, 346) has hit the distalend of the single jaw guide surface 382, the driver 348 will continuemoving distally to cause the gears 368 to rotate via the rack/teeth 358a, 358 b of the driver 348, thereby inducing rotation of the jaws 344,346.

Turning to FIGS. 31-33, another embodiment of the medical system 420 andmedical device 440 are depicted. In this embodiment, medical system 420again includes a drive wire 422 having a distal head 432 which is formedby bending the distal end of the drive wire 422 into the shape shown.The medical system 420 also includes a catheter attachment 430 which isgenerally a tubular member that is connected to the distal end of thecatheter 24 and is used to slidably receive the connection block 426.The catheter attachment 430 includes a pair of openings 434 to provideaccess to the control wire 422 and the connection block 426, whereby atool may be used to hold the connection block 426 in either a retractedor extended position, as further described in copending U.S. Appln. Nos.61/391,878 and 61/391,875, the disclosures of which are herebyincorporated by reference in their entirety.

The medical device 440 includes a housing 442 which is detachablyconnected to the catheter 24 and its catheter attachment 430 via theconnection block 426. The housing 442 slidably receives the pair of jaws444 which are connected to the drive wire 422 via the driver 448. Aswith the previous embodiments, the driver 448 includes a socket 450defined by locking tabs 452 which releasably engage the distal head 432of the drive wire 422. The distal portion of the driver 448 includes aplurality of teeth 458 which define a gear or rack which serves to driverotation of the jaws 444 as previously described. The distal end 466 ofthe driver 448 includes a pocket defined by flanges which are used tofixably engage the biasing strip 490. The housing 442 further defines apair of guiding surfaces or slots 482 which guide the longitudinal androtational movement of the jaws 444.

In this embodiment, the jaws 444 and housing 442 are structured suchthat in the fully retracted position (shown), the jaws 44 project (atleast partially) out distally from the end of the housing 442. As bestseen in FIG. 32, as the distal head 432 is pushed through the lockingtabs 452 they are plastically deformed outwardly to engage the shoulders446 in the housing, and the jaws 444 are fully retracted. In this way,the length of the housing 442 can be shortened, as can the guiding slots482 therein for guiding the jaws 444. It can also be seen in FIG. 32that the distal ends of the jaws 444 include serrations 445 or otherstructures which may aid in gripping tissue.

It is also noted that in this embodiment, as with all prior embodiments,the drive wire 422 is capable of transmitting rotational force andtorque (e.g. from the proximal operating end of the system 20/420)through the distal head 432 and the driver 448 to the jaws 444. As suchthe medical device 440 may be rotated via rotation of the drive wire422, i.e. the jaws 444, jaw pins (e.g. 80), housing 442, and driver 448all rotate as a unit relative to the catheter 24. Inasmuch as thehousing 442 may also be non-rotatably connected to the connection block426 (e.g. depending on the friction therebetween), the connection block426 may also rotate within the catheter attachment 430 (or the catheter,e.g. 24) when the catheter attachment 430 is not used. Accordingly, theorientation of the jaws 444 may be rotated through rotation of theproximal end of the drive wire 422 to orient the jaws relative to thetissue or material being grasped or clipped. It has been found thatforming the drive wire 422 out of a solid nitinol wire has provided goodtorque transmission for rotation of the medical device 440.

It has also been found that having the jaws 444 project at leastpartially out of the housing 442 in their fully retracted positionallows the orientation of the jaws 444 to be visualized so that it iseasier to rotate the jaws 444 prior to opening and closing them aroundtissue. Still further, additional tissue may be encapsulated in the jaws444 before the tissue abuts the distal end of the housing 442. Thedistance which the jaws 444 project from the housing 442 may be varieddepending upon a particular application, i.e. sized to correspond to thethickness of the tissue or the type of procedure being formed to insuregood spacing between the distal ends of the jaws 444 and the distal endof the housing 442.

Yet another embodiment of a driver 548 is shown in FIGS. 34-37, and avariation thereof in FIG. 38. The driver 548 again generally includes aproximal portion 548 p, a distal portion 548 d, and an intermediateportion 548 i therebetween. The proximal portion 548 p again defines asocket 550, here formed by a solid frame or ring 551. The drive wirethus preferably includes a distal head such as the hook 132 (FIGS.20-21) or other shape than can fit through the socket 550 andlongitudinally engage the driver 548. As with some of the priorembodiments, the distal portion 548 d of the driver 548 again includes acentral spine 556 and opposing teeth 558 to form a rack that rotates thegrasping jaws. The distal end 566 of the driver 548 includes a pocket568 defined by two inwardly projecting flanges 570 to engage an optionalbiasing strip, as discussed above.

In this embodiment, the intermediate portion 548 i of the driver 548 isstructured to be deformable, whereby locking legs 552 movelaterally/radially outwardly to engage the housing 543 (FIG. 37) andlock the jaws to prevent them from sliding distally and rotating open.As best seen in FIGS. 34 and 35, the intermediate portion 548 i includesa deformable frame 580 including a proximal member 581, a distal member582, and two opposing lateral members 583, 584, which together define anenclosed intermediate space 587 therebetween. The proximal member 581 isconnected to the driver's proximal portion 548 p via a thin neck 590directly connected to the ring 551 of socket 550, discussed furtherherein. The distal member 582 is connected to the driver's distalportion 548 d via the central spin 556 as shown. The distal member 582further includes deformable areas 585, 586 at its lateral ends, whichare structured to deform and thus serve as living hinges. Preferably theframe 580 plastically deforms to permanently lock the clip.

The locking legs 552 are formed in the intermediate portion 548 i at thelocations where the lateral members 583, 584 meet the distal member 582,and in particular the deformable areas 585, 586. The locking legs 552,alone or in combination with the lateral and distal members 582, 583,584, define extensions 588, 589 of the intermediate space 587, andgenerally have a V-shape or U-shape. Stated another way, theintermediate space 587 has a general C-shape in the normal operatingcondition shown in FIG. 34.

Upon application of a predetermined force differential between thedriver's proximal portion 548 p and distal portion 548 d, the frame 580deforms such that the locking legs move outwardly away from thelongitudinal axis LA, as shown by the arrows in FIG. 35. In particular,the longitudinal distance (denoted by D_(l) in FIG. 35) of theintermediate space increases (as does the overall length of the driver548), and the intermediate space changes from its general C-shape to agenerally rectangular shape. As best seen in FIG. 35, the deformation ofthe frame 580 primarily occurs within the deformable areas 585, 586 ofthe distal member 582, however the lateral members 583, 584 and/or thelocking legs 552 may also slightly deform when the driver 548 isstretched due to the force differential. The force differential isgenerally caused by the user placing a proximally directed force of thedrive wire while the grasping jaws are engaged with tissue (or othermaterial) and engaged with the distal end of the housing such thatfurther proximal withdrawal of the jaws is blocked.

Upon deformation of the frame 580 and rotation of the locking legs 552outwardly, further proximal force on the drive wire will induce a secondforce differential between the driver's proximal portion 548 p and theintermediate portion 548 i, whereupon the neck 590 is designed to failsuch that the drive wire (still attached to proximal portion 548 viasocket 550) can be moved further proximally to detach the deliverycatheter from the housing of the clip, leaving the clip in place andlocked on the tissue. FIG. 37 shows an alternate housing 532, whichincludes a driver guide surface 596. A proximal section 596 p of theguide surface 596 is wider than the distal section 596 d, therebyforming a shoulder 598 that can be engaged by the contact surfaces 553of the locking legs 552. The contact surfaces 553 have been shown asfrusto-conical in shape, but may be pointed or rectangular. Similarly,the shoulder 598 is shaped to be engaged by the legs 552, and isorthogonal to the longitudinal axis LA, and may even be slopedproximally (i.e. to the right on the page in FIG. 37). Multipleshoulders 598 may also be formed to create a one-way ratchetingmechanism.

A variation of the driver 548 described above is shown in FIG. 38. Thisdriver 648 includes a distal portion 648 d and an intermediate portion648 i similar to those described above. In this variation, the neck 690is not designed to fail under a predetermined load (force differential),but rather the proximal portion 648 p of the driver 648 is designed torelease the drive wire under a predetermined force. Here the outer ring651 defining the socket 650 includes a throat 649 that is deflectableand provides the socket 650 with a proximally facing opening. At thesame time, the proximal portion 648 p does not include the locking tabs,but rather the intermediate portion 648 i again defines locking legs 652which operate as described above with reference to legs 552.

The foregoing description of various embodiments of the invention hasbeen presented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the preciseembodiments disclosed. Numerous modifications or variations are possiblein light of the above teachings. The embodiments discussed were chosenand described to provide the best illustration of the principles of theinvention and its practical application to thereby enable one ofordinary skill in the art to utilize the invention in variousembodiments and with various modifications as are suited to theparticular use contemplated. All such modifications and variations arewithin the scope of the invention as determined by the appended claimswhen interpreted in accordance with the breadth to which they arefairly, legally, and equitably entitled.

The invention claimed is:
 1. A medical device for engaging tissue, themedical device comprising: a housing defining an internal passageway anda longitudinal axis extending between proximal and distal ends of thehousing, the housing defining a driver guide surface along the internalpassageway; a first jaw rotatable relative to the housing, the first jawhaving proximal and distal ends; a second jaw rotatable relative to thehousing, the second jaw having proximal and distal ends; an elongateddrive wire; and a driver having a proximal portion engaged with thedrive wire and a distal portion engaged with the proximal ends of thefirst and second jaws, longitudinal movement of the driver rotating thefirst and second jaws relative to the housing, the driver including anintermediate portion positioned between the proximal and distalportions, the intermediate portion including a frame and a locking legconnected to the frame, the frame defining an intermediate space, theframe being deformable such that a predetermined longitudinal forcedifferential between the proximal portion and distal portion of thedriver causes the frame to deform and the locking leg to move away fromthe longitudinal axis into a locking position for engaging the driverguide surface.
 2. The medical device of claim 1, wherein a length of thedriver increases upon deformation of the frame.
 3. The medical device ofclaim 1, wherein the frame circumscribes the intermediate space.
 4. Themedical device of claim 1, wherein the intermediate space has a generalC-shape prior to deformation of the frame, and a generally rectangularshape after deformation of the frame.
 5. The medical device of claim 1,wherein a longitudinal distance of the intermediate space increasesafter deformation.
 6. The medical device of claim 1, wherein the lockingleg rotates away from the longitudinal axis.
 7. The medical device ofclaim 1, wherein the frame plastically deforms.
 8. The medical device ofclaim 1, wherein the frame includes a proximal member extendinglaterally, a distal member extending laterally, and a pair of sidemembers connecting the proximal and distal members.
 9. The medicaldevice of claim 8, wherein the locking leg is connected to the distalmember and one of the side members.
 10. The medical device of claim 9,wherein the distal member defines a deformable area adjacent the lockingleg.
 11. The medical device of claim 9, wherein the distal member,locking leg, and the one side member together deform under thepredetermined longitudinal force differential to move the locking legaway from the longitudinal axis.
 12. The medical device of claim 9,further comprising a second locking leg connected to the distal memberand one of the side members.
 13. The medical device of claim 1, whereinthe locking leg has a general V-shape and defines a portion of theintermediate space.
 14. The medical device of claim 1, furthercomprising a neck interconnecting the proximal portion of the driver andthe intermediate portion of the driver.
 15. The medical device of claim14, wherein the neck is breakable upon a second predeterminedlongitudinal force differential between the proximal portion and theintermediate portion of the driver.
 16. The medical device of claim 15,wherein the second predetermined longitudinal force differential isgreater than the predetermined longitudinal force differential thatdeforms the frame.
 17. The medical device of claim 1, wherein the firstjaw has a proximal end slidably and pivotally connected to the housing,the first jaw slidably received within the internal passageway forlongitudinal movement between an extended position and a retractedposition, and wherein the second jaw has a proximal end slidably andpivotally connected to the housing, the second jaw slidably receivedwithin the internal passageway for longitudinal movement between anextended position and a retracted position.
 18. The medical device ofclaim 17, wherein the proximal ends of the first and second jaws includegears having teeth, and wherein the driver includes corresponding teeththat mesh with the teeth of the jaws.
 19. The medical device of claim17, wherein the proximal ends of the first and second jaws are formed aspinions, and wherein the driver is formed as a rack, whereinlongitudinal movement of the driver and rack rotates the pinions of thefirst and second jaws in their extended positions.
 20. The medicaldevice of claim 1, wherein the driver is formed as a unitary singlepiece.
 21. The medical device of claim 1, wherein the force ofdifferential comprises a proximal force on the proximal portion relativeto the distal portion of the driver.
 22. A medical device for engagingtissue, the medical device comprising: a housing defining an internalpassageway and a longitudinal axis extending between proximal and distalends of the housing, the housing defining a driver guide surface alongthe internal passageway; a first jaw rotatable relative to the housing,the first jaw having proximal and distal ends; a second jaw rotatablerelative to the housing, the second jaw having proximal and distal ends;an elongated drive wire; and a driver having a proximal portion engagedwith the drive wire and a distal portion engaged with the proximal endsof the first and second jaws, longitudinal movement of the driverrotating the first and second jaws relative to the housing, the driverincluding an intermediate portion positioned between the proximal anddistal portions, the intermediate portion including a frame and alocking leg connected to the frame, the frame defining an intermediatespace, the frame being deformable such that a predetermined longitudinalforce differential between the proximal portion and distal portion ofthe driver causes the frame to deform and the locking leg to move awayfrom the longitudinal axis into a locking position for engaging thedriver guide surface; wherein the driver guide surface includes aproximal portion and distal portion and a shoulder between the proximaland distal portions, the shoulder facing proximally, and wherein thelocking leg is positioned to engage the shoulder to limit longitudinalmovement of the driver after the locking leg has been moved laterallyoutwardly by deformation of the frame of the driver.